Weather features and snow cover formation in Moscow during the winter season of 2025/2026

The paper presents the results of comprehensive snow survey observations carried out at the site of the Meteorological Observatory of Moscow State University (MSU Meteorological Observatory) during the winter season of 2025–2026. The meteorological conditions that caused an abnormally late establishment of stable snow cover, extreme snowfalls, and the formation of a record snow depth of 86 cm over a 72-year observation period are analyzed. The stratigraphy, density, and thermal regime of the snowpack were studied in detail at all stages of its evolution, from initial accumulation to intensive spring melting. It was found that repeated alternations of snowfall and frost periods with short-term thaws led to the formation of a multilayered snowpack with several ice crusts and horizons of loosened depth hoar. The dynamics of mean snow density were traced from 138 kg/m³ in freshly fallen snow to 523 kg/m³ in ice crusts at the end of March.